Microphone.



PATENTIIID MAY 23, .1905.

P. J. TARIEL.

MICROPHONE. APPLICATION FILED JUNE 30,1904.

. WWW

UNITED STATES Patented May 23, 1905.

PATENT OFFICE.

MICROPHONE.

SPECIFICATION forming part of Letters Patent No. 790,603, dated May 23, 1905.

Application filed J 11110 30, 1904- $erial No. 214,813.

To all whom it may concern.-

Be it known that 1, PAUL J ULIEN TARIEL, doctor of medicine, of 19 Rue Klber. Issyles-Moulineaux, Seine, Republic of France, have invented Improvements in Microphones, of which the following is a exact description.

This invention relates to a microphone the particles of carbon of which are in the form of pellicles or films, thereby greatly increasing the sensitiveness of the apparatus. These pellicles are obtained by taking plates of coal of about from one-tenth and a half to twotenths of a millimeter thick which are perfectly plane and smooth and which are then broken between the fingers. The so-obtained pellicles are passed through a special sieve in order that the pellicles of more than one millimeter of surface will remain in the sieve. Those are the only ones which are used. The use of these pellicles of carbon has very important technical advantages.

First. Thesensitiveness of the microphone depends upon the largest number of contactpoints between the vibratory surfaces. Now the number of contact-points is greater between plane surfaces than between rounded bodies or granulated bodies.

Second. The pellicles placed in a microphonic receptacle will never alter their relative positions the one relatively to the other, so that the apparatus will never require to be adjusted again.

Third. The pellicles being all of uniform thickness cannot become blocked up in the apparatus when the latter is kept in a vertical position. On the contrary, as they will all be placed vertically they will rest the one above the other with their edges so that the slightest impulse will make them easily vibrate.

Fourth. The almost complete suppression of the small voltaic arcs which in the ordinary microphones continue to lead the current, even after the separation of the granulations. On the contrary, the ordinary granulations far from increasing the sensitiveness of the apfull, clear, and

paratus when the latter is vertically arranged fall to the bottom of the receptacle and collect there.

Reference is made to the accompanying drawings, showing the carbon pellicles of my invention and one form of transmitter in which they are employed, in which similar characters of reference indicate corresponding parts in all the figures.

Figure 1 is a side elevation of the transmitter. Fig. 2 is a central section through the same. Fig. 3 is a plan view of the cylinder 6 for containing the pellicles, and Fig. 4 shows the pellicles as disposed within one of the pockets of the cylinder.

A cup at encircles a cylinder 6, which is provided with pockets containing pellicles 0 of carbon, having preferably a multitude of promiscuous shapes, as indicated in Fig. 4E. The front diaphragm is shown at d and the back plate or rear diaphragm at 6. By means of screws f a ring 9, which may be of rubber or other resilient material, is pressed against the front diaphragm cl. The mouthpiece is shown at 71. Bolts is pass entirely through the ring g, diaphragm (Z, and cup a and engage a plate 7' of conducting material, and connected with it is a binding-post '5. Another binding-post, Z, is in direct electrical communication with some of the carbon pellicles.

I claim- 1. A microphone characterized by the use of'pellicles of coal formed as small irregular plates, With the purpose to' increase the sensitiveness of the apparatus, substantially as described.

2. In a microphone, the combination of a plurality of flat pellicles of carbon loosely engaging each other, thereby forming a plurality of imperfect contacts.

The following Specification of my improvements in microphones signed by me this 17th day of June, 1904:-

PAUL J ULIEN TARIEL.

Witnesses:

HANsoN (J. Ooxn, MAURICE H. PIGNET. 

